Which code represents Distant control relay?

• A. D
• B. DG
• C. DV
• D. EM

Answer: (C)

In signaling equipment labeling, relays are identified by two-letter codes that reflect their function and role. The first letter indicates the broad function, and the second letter specifies the particular device within that function. The Distant control relay is denoted by the code DV, because it directly names the distant control type and distinguishes it from other devices that might share the same broad function but serve different purposes. The other options either give only the generic distant function (D), point to a different relay within the distant family (DG), or refer to another category altogether (EM, such as emergency-related functions). So DV is the label that exactly matches the Distant control relay.